Turbine engine and control method

Patent metadata

Field	Value
Publication number	US-2016298486-A1
Application number	US-201415037374-A
Country	US
Kind code	A1
Filing date	Nov 7, 2014
Priority date	Nov 19, 2013
Publication date	Oct 13, 2016
Grant date	—

Abstract

A turbine engine includes a compressor, a combustion chamber, first and second turbines downstream from the combustion chamber, a first rotary shaft constrained to rotate at least with the compressor and the first turbine, a second rotary shaft constrained to rotate with the second turbine, the second rotary shaft nevertheless being free to rotate relative to the first rotary shaft, and a regulator for controlling the feed of fuel to the combustion chamber. The regulator cuts off the feed of fuel to the combustion chamber if the speed of rotation of the second rotary shaft exceeds a maximum threshold that varies as a function of at least one indicative physical parameter associated with mechanical power being extracted from the combustion gas by the second turbine. A method of regulating the turbine engine is also presented.

First claim

1 . A regulation method for regulating at least one turbine engine that comprises at least:
a compressor; a combustion chamber downstream from the compressor; first and second turbines downstream from the combustion chamber; a first rotary shaft constrained to rotate at least with said compressor and said first turbine; a second rotary shaft constrained to rotate with the second turbine, the second rotary shaft being free to rotate relative to the first rotary shaft; and a regulator for controlling a fuel feed to the combustion chamber; wherein said regulator cuts off the fuel feed to the combustion chamber if the speed of rotation of said second rotary shaft exceeds a maximum threshold that varies as a function of at least one indicative physical parameter associated with mechanical power being extracted from the combustion gas by the second turbine, and; wherein said maximum threshold for the speed of rotation of the second rotary shaft is reduced when said indicative physical parameter exceeds a higher threshold and when said indicative physical parameter passes below a lower threshold.

2 . A regulation method according to claim 1 , wherein said indicative physical parameter is torque transmitted by the second rotary shaft.

3 . A regulation method according to claim 1 , wherein said indicative physical parameter is a speed of rotation of the first rotary shaft.

4 . A regulation method according to claim 3 , wherein said maximum threshold for the speed of rotation of the second rotary shaft varies as a function at least of said speed of rotation of the first rotary shaft, and also as a function of ambient pressure and/or temperature.

5 . A regulation method according to claim 1 , wherein said indicative physical parameter is a pressure downstream from said compressor.

6 . A regulation method according to claim 1 , wherein said indicative physical parameter is a temperature downstream from said combustion chamber.

7 . A regulation method according to claim 1 , wherein said indicative physical parameter is a flow rate of fuel supplied to the combustion chamber.

8 . A regulation method according to claim 1 , wherein said indicative physical parameter is a flow rate of air passing through said compressor.

9 . A regulation method according to claim 1 , wherein said indicative physical parameter is a movement of a control member for controlling the engine.

10 . A regulation method according to claim 1 , wherein, below said higher threshold for the speed of rotation of the first rotary shaft, a warning is recorded if said indicative physical parameter exceeds a warning threshold substantially lower than its maximum threshold.

11 . A regulation method according to claim 1 , wherein said maximum threshold for the speed of rotation of the second rotary shaft decreases gradually with an increase in said indicative physical parameter between an intermediate threshold and its higher threshold.

12 . A data medium including a set of instructions suitable for being executed by a programmable digital regulator in order to perform a regulation method according to claim 1 .

13 . A turbine engine comprising:
a compressor; a combustion chamber downstream from the compressor; first and second turbines downstream from the combustion chamber a first rotary shaft constrained to rotate at least with said compressor and said first turbine; a second rotary shaft constrained to rotate with the second turbine, the second rotary shaft nevertheless being free to rotate relative to the first rotary shaft; and a regulator for controlling a fuel feed to the combustion chamber and configured to cut off said fuel feed if a speed of rotation of said second rotary shaft exceeds a maximum threshold that varies as a function of at least one indicative physical parameter associated with mechanical power being extracted from the combustion gas by the second turbine, and; wherein said maximum threshold for the speed of rotation of the second rotary shaft is reduced when said indicative physical parameter exceeds a higher threshold and when said indicative physical parameter passes beneath a lower threshold.

Assignees

• Turbomeca

Inventors

• Langford Stephen
• Lescher Fabien

Classifications

• F05D2220/329

  in helicopters · CPC title

• F05D2270/021

  to prevent overspeed · CPC title

• F01D21/02 Primary

  Shutting-down responsive to overspeed · CPC title

• F02C3/10

  with another turbine driving an output shaft but not driving the compressor · CPC title

• F05D2270/091

  in particular sudden load loss · CPC title